Re: [linux-sunxi] [PATCH v3 10/13] spi: sunxi: merge sun4i and sun6i SPI driver

From: Julian Calaby
Date: Mon Jun 13 2016 - 19:44:22 EST


Hi Michal,

On Tue, Jun 14, 2016 at 3:46 AM, Michal Suchanek <hramrach@xxxxxxxxx> wrote:
> The drivers are very similar and share multiple flaws which needed
> separate fixes for both drivers.
>
> Signed-off-by: Michal Suchanek <hramrach@xxxxxxxxx>
> ---
> drivers/spi/Kconfig | 8 +-
> drivers/spi/Makefile | 1 -
> drivers/spi/spi-sun4i.c | 156 +++++++++++--
> drivers/spi/spi-sun6i.c | 598 ------------------------------------------------
> 4 files changed, 143 insertions(+), 620 deletions(-)
> delete mode 100644 drivers/spi/spi-sun6i.c
>
> diff --git a/drivers/spi/spi-sun4i.c b/drivers/spi/spi-sun4i.c
> index 0b8e6c6..c76f8e4 100644
> --- a/drivers/spi/spi-sun4i.c
> +++ b/drivers/spi/spi-sun4i.c
> @@ -279,9 +321,14 @@ static int sunxi_spi_transfer_one(struct spi_master *master,
> reg = sunxi_spi_read(sspi, SUNXI_TFR_CTL_REG);
>
> /* Reset FIFOs */
> - sunxi_spi_write(sspi, SUNXI_TFR_CTL_REG,
> - reg | sspi_bits(sspi, SUNXI_CTL_RF_RST) |
> - sspi_bits(sspi, SUNXI_CTL_TF_RST));
> + if (sspi->type == SPI_SUN4I)
> + sunxi_spi_write(sspi, SUNXI_TFR_CTL_REG,
> + reg | sspi_bits(sspi, SUNXI_CTL_RF_RST) |
> + sspi_bits(sspi, SUNXI_CTL_TF_RST));
> + else
> + sunxi_spi_write(sspi, SUNXI_FIFO_CTL_REG,
> + sspi_bits(sspi, SUNXI_CTL_RF_RST) |
> + sspi_bits(sspi, SUNXI_CTL_TF_RST));

If we're already doing different stuff for each generation of the IP,
why not just use the register offsets and bit definitions directly?

>
> /*
> * Setup the transfer control register: Chip Select,
> @@ -427,7 +473,19 @@ static int sunxi_spi_runtime_resume(struct device *dev)
> goto err;
> }
>
> - sunxi_spi_write(sspi, SUNXI_TFR_CTL_REG,
> + if (sspi->rstc) {
> + ret = reset_control_deassert(sspi->rstc);
> + if (ret) {
> + dev_err(dev, "Couldn't deassert the device from reset\n");
> + goto err2;
> + }
> + }
> +
> + if (sspi->type == SPI_SUN4I)
> + reg = SUNXI_TFR_CTL_REG;
> + else
> + reg = SUNXI_GBL_CTL_REG;
> + sunxi_spi_write(sspi, reg,
> sspi_bits(sspi, SUNXI_CTL_ENABLE) |
> sspi_bits(sspi, SUNXI_CTL_MASTER) |
> sspi_bits(sspi, SUNXI_CTL_TP));

Same here.

> @@ -491,10 +558,37 @@ static int sunxi_spi_probe(struct platform_device *pdev)
> }
>
> sspi->master = master;
> - sspi->fifo_depth = SUN4I_FIFO_DEPTH;
> - sspi->type = SPI_SUN4I;
> - sspi->regmap = &sun4i_regmap;
> - sspi->bitmap = &sun4i_bitmap;
> + if (of_device_is_compatible(pdev->dev.of_node, SUN4I_COMPATIBLE)) {
> + sspi->fifo_depth = SUN4I_FIFO_DEPTH;
> + sspi->type = SPI_SUN4I;
> + sspi->regmap = &sun4i_regmap;
> + sspi->bitmap = &sun4i_bitmap;
> + } else if (of_device_is_compatible(pdev->dev.of_node,
> + SUN6I_COMPATIBLE)) {
> + sspi->fifo_depth = SUN6I_FIFO_DEPTH;
> + sspi->type = SPI_SUN6I;
> + sspi->regmap = &sun6i_regmap;
> + sspi->bitmap = &sun6i_bitmap;

Can you store data in the match table instead of doing this?

> + } else {
> + const char *str = NULL;
> + int i = 1;
> +
> + of_property_read_string(pdev->dev.of_node, "compatible", &str);
> + dev_err(&pdev->dev, "Unknown device compatible %s", str);
> + /* is there no sane way to print a string array property ? */
> + if (of_property_count_strings(pdev->dev.of_node, "compatible")
> + > 1) {
> + while (!of_property_read_string_index(pdev->dev.of_node,
> + "compatible", i,
> + &str)) {
> + pr_err(", %s", str);
> + i++;
> + }
> + }
> + ret = -EINVAL;
> + goto err_free_master;
> + }
> +
> master->max_speed_hz = 100 * 1000 * 1000;
> master->min_speed_hz = 3 * 1000;
> master->set_cs = sunxi_spi_set_cs;

Thanks,

--
Julian Calaby

Email: julian.calaby@xxxxxxxxx
Profile: http://www.google.com/profiles/julian.calaby/